Electron-discharge device



May 25 1926. 1,586,162 .1. c. R. PALMER ELECTRON DISCHARGE DEVICE Original Filed March 29. 1923 lm/enfor. v J0 e/ CR. Pa/mer by W my Patented May 25, 1926.

' UNITED STATES PATENT orr ca.

JOEL O. B. IPALMER, 01? NEW ROCHELLE, NEW YORK, ASSIGNOR TO WESTERN ELEG- TBIG COMPANY, INCORPORATED, OF NEW YORK, N. Y., A. CORPORATION 01' NEW YOBK.

nnnc'rnon-msomen DEVICE Application filed March 29, 1928. Serial No. 628,407. Renewed October 10, 1925.

This invention relates to electron discharge devices and has as its object an improved method of heating the cathodes of such devices.

5 This object is attained by surrounding the cathode by a wire helix so connected with both the input and output circuits of the device that some of the energy from the output circuit is supplied to the helix and some 0 to the in ut circuit whereby the device acts as an oscillator, and the highfrequency energy delivered to the helix induces current in the cathode to heat it, thereby rendering I it thermionically active.

Referring now to the drawings, the single figure thereof discloses an embodiment of the invention. 1

Within the enclosing vessel are arranged the cathode 11, the control electrode 0 12 and the anode 13. The cathode prefer;

ably comprisesatube of metal and may be coated on its external surface with a layer of thermionically active material. The control'electrode 12 comprises ahelix of conductin wire and is so placed as to enclose thecat ode 11. The anode 13 is shown in the form of a plate arranged adjacent the cathode and control electrode.

The anod'e'13 is electrically connected to the cathode 11 through they primary of a transformer 14, battery 15 and inductance 16. The cathode 11 is electricallyconnected to the .helix 12 through the. inductance 17 and the secondary of the transformer 18.

i The terminals of the helix 12 are connected in circuit with the inductances 19 'and 20 which are 0 eratively associated with the inductanoes 1 and 16 respectively so that the, circuit comprising them and the helix 12-,is

' inductively connected to both the input and is s unted around the inductances 16 and 17.

In the operation of this device, the oathode 11 is initially heated by current induced therein from high frequency currents supplied to the helix from a source of high freuency (not shown). The cathode becomes t ermionically active and a spacecurrent is established between it and the anode 13in the usual manner. There are also set up in the output circuit high frequency oscillations which by means of the inductances 16 and 20, are-fed to the circuit including the output circuits of the device. A capacity 21 be helix 12, thus supplying current for maintaining induced currents in the cathode 11 to keep it heated.- High frequency current is also supplied to the input circuit through the medium'of the inductances 19 and 17,

cuit through the transformer 14.

This arrangement dispenses with the need i of a battery for heating the filament and allows the utilization of the high frequency energy cathode. The invention claimed is 1. In combination, an electron discharge device having a cathode, an anode and acontrol electrode, said control electrode com prising a wire helix surrounding said cathode, an input circuit and an output circuit, mean for supplylng alternating current to said helix from said output circuit, and

means associated with said cathode and said of the output circuit to heat the control electrode for controllin the output of said device in accordance wit signals.

2. In combination, an electrondischar e device having a hollow cathode, an ano e and a control electrode,- s'aid control electrode comprising a wire helix surrounding said cathodeflm input circuit and an output circuit, means for inductively connecting said helix and said output circuit, and means for impressing a difference of potential corresponding to signaling varlations tgeen said cathode and said control electro e.

.3. In combination, an electron dischar e device having a hollow cathode, an ano e,

circuit connections between said anode and cathode comprising an inductance, a control electrode comprising a helix surrounding said cathode and in circuit with an induc tance operati'vely related to said first inductance, circuit connections between said control electrode and said cathode com rising an inductance operatively relate to said second inductance, and means associated. with said cathode and said control electrode for controlling the output of said device in accordance with signals.

4. In combination, an electron discharge device having an anode, a-cathode, and a control electrode, said control electrode com prising a wire helix surrounding said cathode, an input circuit, an output circuit, said helix being inductively connected to both said input and output circuits, and means for impressing a diflerence of potential corresponding to signaling variations between said helix and said cathode.

5. In combination, an electron discharge device comprising a cathode, an anode and a control electrode surrounding said cathode, an input circuit and an output circuit, said circuits being inductively connected, means for supplying high frequency currentto said control electrode from said output circuit whereby the cathode is heated by induced currents, and means for impressing a difference of potential varying in accordance with; signals between said cathode and said control electrode.

6. In combination, an electron discharge device comprising an anode, a cathode and a control electrode, said cathode and control electrode being inductively related to each other, an input circuit, an output circuit, means for supplying high frequency current to said control electrode from said output circuit, and means for impressing a difference of potential corresponding to signaling variations between said cathode and control electrode. 7. In combination, an electron discharge device comprising an anode, a cathode, and a control electrode, said, cathode and control electrode being inductively related, an input circuit, an output circuit, means for supplying high frequency current to said control electrode from said output circuit, and means for impressing a difierence of .potential corresponding to signaling variations between said cathode and control electrode. 8. In combination, an electron discharge device comprising an anode, a cathode, and a control electrode, said cathode and control electrode being inductively related, an input circuit, an output circuit, said circuits being inductively connected, means for supplying high frequency current to said control electrode from said output circuit, and means associated with said control elecsaid trode and said cathode for controlling the output of said device in accordance with signals.

- 9. In combination, a thermionic tube including an anode and a cathode, means for inductively heating the cathode, an external circuit utilizing said means as an electrode of the tube, and means for controlling said circuit in accordance with signals.

In witness whereof, I hereunto subscribe my name this 24 day of March A. D., 1923.

JOEL C. R. PALMER. 

